Individuals with Cancer Have Lower Rate of Alzheimer’s Disease

A large study has indicated that individuals who are diagnosed with cancer have a significantly lower rate of Alzheimer’s disease (AD) and treatment with chemotherapy is associated with an even lower risk. These results were recently presented at the Alzheimer’s Association 2013 International Conference. The press release from the Alzheimer’s Association can be found here:

The Alzheimer’s Association has written that “A growing body of evidence suggests a possible association of cancer with reduced risk for Alzheimer’s disease; until now, whether the association differs between cancer types or is modified by cancer treatment is unknown.”

To further explore this issue, researchers associated with the Veteran’s Association (VA) Boston Healthcare System and colleagues analyzed data from the health records of veteran’s who were 65 years or older. The data included 3,499,378 veterans in the VA health care system between 1996 and 2011. When the study was initiated, no participants had dementia. Individuals were followed for over 5.65 years.

82,028 veterans were diagnosed with Alzheimer’s disease during the duration of the study.
76% of those diagnosed with Alzheimer’s did not have a diagnosis of cancer
Certain type of cancers were associated with different reductions in the rate of Alzheimer’s.
Liver cancer was associated with a 51% reduced rate of Alzheimer’s, pancreatic cancer a 44% reduced rate, esophageal cancer a 33% reduced rate, myeloma a 26% reduced rate, lung cancer a 25% reduced rate and leukemia a 23% reduced rate.
Melanoma, prostate and colorectal cancers were not associated with a reduced rate of Alzheimer’s disease.
Alzheimer’s disease was the only age-related health issue that appeared to be reduced with a diagnosis of cancer. In fact, those diagnosed with cancer had increased rates of non-Alzheimer’s dementia, osteoarthritis, stroke, cataracts and macular degeneration.
Chemotherapy, but not radiation, reduced the risk of Alzheimer’s disease by 20-45%, depending upon the type of cancer. The association between Alzheimer’s disease and prostate cancer was not affected by chemotherapy.

The researchers stated that “”The results of this study are interesting because they could help focus future research onto the specific pathways and treatment agents involved in the individual cancers that are associated with a reduced risk of Alzheimer’s. This could potentially open new therapeutic strategies for Alzheimer’s prevention and treatment.”

Reference: Alzheimer’s Association 2013 International Conference. Cancer history and chemotherapy are associated with decreased risk of Alzheimer’s. Press Release. Accessed July 21, 2013 at: